Roof trusses are typically assembled on truss assembly tables having a work surface interrupted by various slots or gaps. Some of these gaps are for use with adjustable jigging assemblies and some are to allow space for lift out assemblies to lift the truss from the table and away from the table. The slots for the lift out assemblies tend to be large, often three inches or wider, and can create problems with the assembly of the truss. Connector plates, placed on the bottom side of the truss and abutting the table work surface may fall into or tilt into the gaps. Other connector plates may remain in position but not be fully supported by the work surface because of the gaps. In such instances, when a gantry press is rolled over the truss assembly, the connector plates are not properly pressed into the wooden truss members. For example, the connector plates may not “bite” into the members enough to remain in place during transfer of the truss assembly from the table to another material handling device. This is especially true in roof truss assembly devices where the system is not designed to completely press the connector plates into the truss members. Typically in roof truss construction the connector plates are only partially pressed into the truss assembly at the truss assembly table. Once the truss assembly is set in position by the partially embedded plates, the truss is transferred to another press, such as a finish roller press, to complete the embedding process.
Conventionally, truss assembly tables employ mechanical lift out assemblies having rollers that vertically lift the assembled truss off of the work surface. The truss is then manually pulled or pushed along the rollers toward another material handling device such as a conveyor. Some lift out assemblies are movable to a sloped raised position so that gravity moves or aids in the movement of the truss. The lift out assemblies use skate rollers or other wheels mounted on the lift out rails to ease sliding of the truss from the lift out assembly rails to another material handling device. These skate wheels may be fragile, however, and can be damaged requiring maintenance and replacement.
It would be desirable to provide a system which reduces or eliminates the problems presented by the lift out assembly gaps and which eliminates the use of fragile wheels mounted on lift out assemblies.